Electric igniting mechanism for internal-combustion engines



A. A. KENT., ELECTRIC IGNITING MECHANISM FOR INTERNAL COMBUSTIONENGINES.

APPLICATION FILED APR. 9, 19]].

WITNESS ATTORNEYS A. A. KENT. ELECTRIC IGNITING MECHANISM FOR INTERNALCOMBUSTION ENGINES. APPLICATION men APR. 9, 1912.

1,341, 1 36. Patented y 25, 1920 2 SHEETSSHEET 2- ATTORNEY ARTHURATWATEB KENT, OF ROSEMONT, PENNSYLVANIA ELECTRIC IGNITING MECHANISM FORINTERNAL-COMBUSTION ENGINES.

Application filed April 9, 1917.

To all whom it may concern:

Be it known that I, ARTHUR A'rwa'rnn KENT, a citizen of the UnitedStates, and a resident of Rosemont, Montgomery county, State ofPennsylvania, have invented certain new and useful Improvements inElectric Igniting Mechanisms for Internal-Com bustion Engines, of whichthe following is a specification.

My invention relates to devices for producing a spark in the cylindersof internal combustion engines and to the regulation of the time atwhich the spark is formed, in order that the most efiicient performanceof the engine may result. It is common in op erating an internalcombustion engine, such as one used in an automobile, the speed of whichvaries within wide limits, to manually rotate and adjust the entirecontact maker with respect to the driving shaft of the engine to causethe igniting spark to be formed at an earlier period in the compressionstroke, .when the engine is running at high speeds, than it is formedwhen the engine is running at low speeds.

An object of the present invention is to provide a mechanism which willautomatically vary the time at which the spark is produced substantiallyproportionally to variations in the speed of the engine.

My improved device consists of a combined contact maker, distributor andspeed responsive or spark controlling device, all arranged within acasing in a simple and compact manner, the speed responsive device beingoperable to advance the 'cam, which operates the contact device, and atthe same time to also advance the arm of the distributer by means ofwhich the various c linders are consecutively-put into series with thesecondary winding of the induction coil the primary winding of which isclosed ant. opened very ra idly by the contact device.

In my prior atent No. 1,192,788, dated July-25, 1916, is illustrated oneform of an automatic device for performing generally the functions aboveindicated, and my present invention relates to certain im rovementstherein whereby the device is simplified, the construction is renderedvery much more compact, and the work of assembling is simplified with aconsequent reduction in the cost of manufacture.

Another object of my invention is to so construct the speed. responsivedevice that Specification of Letters Patent.

Patented May 25. 1920.

Serial No. 160,651.

the weights of the parts acted upon by centrifugal force may bematerial]. reduced and the action thereof may be ma e more sensitive.Another object of my invention is to make the cam, which operates thecontact device, substantially a part of the speed responsive devicerather than one which is operated by a speed responsive device throughthe intermediary of some connec tion.

Another object of my invention is to make the whole mechanism much morenearly-balanced to thereby avoid vibration in the mechanism when theparts are being driven at a rapid speed. A further object of myinvention is to dispense with any bearing of the contact maker cam inthe base upon which the contact maker is supported, said cam beingmounted and supported on the driving shaft.

A further object of my invention is to provide a construction in whichthe main shaft is mounted in a single bearing extending to a point verynear the contact device cam, and in which the main shaft itselfsubstantially supports the speed responsive device, the cam for thecontact maker, and the distributer arm of the distributing mechanism.

Other objects of my invention will appear in the specification andclaims below.

Referring to the drawings forming apart of this specification and inwhich the same reference numerals are employed throughout the variousviews to designate the same rts, Figure 1 is a plan view of the top ofhe mechanism; Fig. 2 is a plan view of the same with the cap in whichthe distributer contact points are mounted, removed to expose thecontact maker; Fig. 3 is a plan view of the mechanism with thedistributer arm and the base of the contact maker, together with theparts attached thereto, removed and disclosing a plan view of the speedres on sive device or controllin mechanism; ig. 4 is a plan view of theottom part of the casing with the controlling mechanism and drivingshaft removed.

Fig. 5 is a vertical sectional view on the line 5-5 of Fig. 1, the speedresponsive mechanism or governing mechanism being not sectioned butshown in side elevation; Fig. 6 is an inverted or bottom view of thecontrolling mechanism showing the positions of the weights and sgg'ingswhen the driving shaft is stationary; ig. 7 is a vertical sectionalviei. through the lower portion of the casing and through the governingmechanism, same being taken on the line 7-7 of Fig. 3, the top of themain portion of the drivin shaft, however, being not sectioned; and Fig.8 is a transverse sectional view of the governor or speed res onsivemechanism taken on the line 8-8 of ig. 6.

The mechanism forming the subject matter of this invention is inclosedwithin a casing 1, which casing comprises two parts, a cup-shapedportion 2, preferably of metal, and by which is inclosed the speedresponsive or spark controllin mechanism 3, and a cap 4, preferably ofinsulating material, in which is embedded the terminals and contactplates 15 of the secondar circuit of the distributing mechanism 5. hiscap 4 covers and incloses the contact maker 6 and the distributermechanism 5. The contact maker is preferably mounted upon a metallicbase or plate 7, secured by screws 888 to the top of the cup-shapedportion 2, and the cap 4 is preferably seated on the top of the baseplate 7 and positioned with respect thereto by lugs 99 molded on thebottom edge of the cap 4 and adapted to register the corres ondingopenings 1010 in the base plate For holdi the cap 4 fixedly to butreadily removable rom the base plate 7 and the cup-shaped portion 2, Ipreferably provide a air of spring clips 11-11 pivoted on suitable pivotpins 12-12 on opposite sides of the cup shaped portion 2 of the casing,the upper ends of said spring clipsfll being bent to form spring hooksadapted to snap into recesses 13-13 provided therefor on opposite sidesof the cap or cover 4. The cap 4 is preferably provided with a convextop surface from which extend four hollow projections 14 equi-distantfrom the center or axis of the cap 4 and equi-distant from each other,each being adapted to fit over and hold respectively one of the leads ofthe secondary ci'rcu' extending each respectively to a cylinde? of aninternal combustion engine. These leads passing through theprojection 14are res ectively connected with the terminal an contact points or plates15 embedded in the cap 4 and arranged to cooperate with the distributerarm 16 of the distributing mechanism 5. At the center of the cap 4, andprojecting vertically therefrom. is a fifth hollow projection 17 adaptedto fit over the lead which extends to the secondary winding of theinduction coil, and which affords communication with the centralterminal and contact point or plate 18 of the distributor mechanism alsoembedded in the cap 4 as clearly appears in Fig; 5.

The cup-shaped portion 2 of the casing 1 is preferably provided with acentrally arranged outwardly projecting hub -19, by meansv of whichthewhole device may be suitably mounted and supported, and in it issuitably journaled the driving shaft 20 provided at its lower end with aclutch or couplin 21, by means of which it may be attache to the drivingshaft of aninternal combustion engine.

Within the cup-shaped portion 2 of the casing and extending upwardlyfrom the bottom thereof and in an axial alinement with the shaft 20 andhub 19 is a lug or projection 22, extendin well toward the to of thecup-shaped portion 2 and in it the s aft 20 smoothly fits. This lug orprojection 22 forms in fact a continuation of the hub 19, but Within thecasing, and with the hub or projection 19 provides the journal for theshaft 20, which extends to substantially the top of the main portion ofthe driving shaft 20. Near the top of the main portion of the drivingshaft 20 a plate 23 is rigidly united with the shaft 20, the plate 23being preferably substantially square. This plate 23 forms the supportfor and is a part of the speed responsive mechanism 3. This plate 23rests on the top of the lug or projection 22, the upper end of the lug22 forming the thrust or step bearing upon which the shaft 20 of thespeed responsive mechanism 3 is supported.

Depending from the plate 23 is a pivotal stud 24 forming a pivot pin towhich one end of a substantiallyyL-shaped weight 25 is attached. Thesaid weight 25 is, however, spaced from the plate 23 by a collar orwasher 26.

On the diametrically opposite side of the plate 23 (with respect to theaxis of the shaft 20) is a similar depending stud 27 forming a pivotalsupport for a similar substantially L-shaped weight 28, said weightbeing similarly spaced from the plate 23 by a similar collar or washer29. These weights 25 and 28 are exactly alike but the laterallyextending portions 25' and 28 thereof extend in opposite directions onopposite sides of the axis of the shaft 20, and

, said portions 25 and 28 are slighlty curved to approximatesubstantially the arc of a circle whose center is the axis of the shaft20.

Above the plate 23 the shaft 20 is substantially reduced in, diameter toform an extension 30 integral with said shaft 20 and forming a supportor bearing for the combined contact maker31, distributor arm sup port 32and upper plate 33 of the speed responsive device 3.. The contact makercam 31 and distributor arm support 32 are preferably made of suitablemolded insulating material, such as bakelite, and is molded di rectly onto and made unitary with the upper plate 33 of the governing mechanismor speed responsive device 3. This upper plate 33 is clearly shown inFig. 3. and is This plate is preferably punched from sheet metal and isprovided with a circular hub 34 struck up out of the metal itself, asplainly shown in Figs. 7 and 8, said hub or annular projection 34 havingan aperture 35 through the hub thus formed and projecting above the topsurface of the plate 33. The plate 33 is so provided with a largercircular recess 36 concentric with the aperture 35 below the smooth orbottom side thereof. The combined bakelite cam 31 and distributer arm 32are molded into, over and around the hole 35, recess 36 and projectionor hub 34 which form a considerable surface on the plate 33 and in thisway the same are rigidl united and anchored to the plate 33, as cl earlyshown in Fig. 7. This molded cam 31 and distributer support 32 has alsomolded in it at the same time an axial hole or opening 37 to smoothlyfit over the reduced extension 30 of the shaft 20. The hole 37 ispreferably deeper than the length of the said reduced extension 30, sothat when the unitary contact maker cam 31 distributer arm support 32and upper plate 33 of the governor mechanism are slipped over thereduced extension 30 the plate 33 bears against the shoulder between themain portion of the shaft and the reduced extension and is thussupported by the shaft 20 in axial alinement therewith.

The upper plate is provided with a depending stud 38 passing through anareshaped slot 39 in the bottom plate 23, the center of said arc-shapedslot being the axis of the shaft 20 and this stud' 38 forms a pivot fora substantially L-shaped weight 40, like the weights 25 and 28, having alaterally extending portion 40 overlying or overlapping thecorresponding portion 25 of the weight 25. The weights 25 and 40 arepivoted together on a stud 41 riveted to the weight 25 and extendingfreely through the weight 40 and through an arc-shaped slot 42 in thebottom plate 23, the center of said arc-shaped slot 42 being the axis ofthe stud 24. This stud 41 is provided with a head 43 on the uppersurface of the bottom plate 23 the diameter of said head being greaterthan the width of said slot 42.

()n the diametrically opposite side of the top plate 33 and at the samedistance from the axis of the shaft 20 that the axis of the stud 38 is,is riveted a depending stud 44 passing through the plate 33 through anarcshaped slot 45, the center of curvature of which is the axis of theshaft 20. and passing.

below the bottom plate 23, forms a pivot for a fourth substantiallyL-shaped weight 46 like the weights above described, but whose laterallyextending portion 46' overlies or overlaps the laterallv extendingportion 28' of the weight 28. The weights 40 and 46 are between theweights 25 and 28, respectively, and the bottom plate 23. Theoverlapping portions 46 and 28' of the weights 46 and 28 are pivotedtogether by a stud 47, riveted to the wei ht 28, which stud 47 passesfreely throng a circular opening in the weight 46 and thence through anarcshaped slot 48 in the bottom plate 23. The center of said arc-shapedslot 48 is the axis of the stud 27 and this stud 47 is provided with ahead 49 on the top of the bottom plate 23 of larger diameter than thewidth of the slot 48.

The depending stud 38 passes freely through the L-shaped Weight 40 andbelow it is provided with a kerf 50 on the side thereof adjacent theshaft 20, and into it one end of a coil spring 51 is booked, the otherend of said spring 51 being attached to a stud 52 depending from theunder side of the plate 23 (see Fig. 8). The other depending stud 44also passes freely through the weight 46 and is provided with a similarkerf 53 into which is hooked one end of the coil spring 54, the otherend of which is attached to a stud 55 depending from the side of theplate 23 and diametrically opposite the said stud 52. In their normalpositions, that is to say, when the shaft 20 is stationary, these coiledsprings 51 and 54 are in axial alinement with each other and theirlongitudinal axes pass through the axis of the shaft 20.

The four weights above described are all loosely mounted at all theirrespective points of pivotal connection to the plates 23 and 33 and toeach other, as above described, and the studs pass freely through theirrespective arc-shaped slots in the plate 23; between the weights 25 and40 and between the weight 40 and the plate 23 are thin spacing washers56, and similarly between the weights 28 and 46 and between the weight46 and the plate 23 are like thin spacing washers 56 so that theseweights do not bear against each other nor against the plate 23.

A similar thin washer 56 is-placed on the stud 38 between the weight 46and the bottom plate 23; and also one on the stud 44 between the weight46 and the bottom plate 23. These washers thus greatly diminish. keepthe weights out of substantial rubbing or sliding engagement with theplate 23 and each other, reducing the liability of their sticking,reducing friction, and rendering them sensitive. The relatively loosepivotingof the weights to their studs and to each other also contributesto the same end.

It will be observed that the said weights are all on the under side ofthe bottom plate 23 surrounding the lug or projection 22, that is tosay, that the bearing for the shaft 20 extends within the weights and upto and against the bottom plate 23 of the speed responsive device. Thisdisposition of the parts supports the weights below the top of the shaft20 and below the top of the bearing for the shaft 20, thus reducing veryma terially the distance which' said bearing extends .below the bottomof the cup-shaped portion 2; reducing the height of the cu shaped ortion2 of the casing; and firm y supporting the shaft in a bearing extendingu to a point adjacent the operative portion of the contact maker cam 31.This construe tion also makes it possible to support the contact makercam and distributer arm support substantially directly upon the shaft 20dispensing with any bearing therefor in the base plate 7 of the contactdevice, thus further reducing cost of manufacturing.

Above the base plate 7 of the contact device and upon the to surfacethereof is supported the contact evice or contact maker 6. This contactmaker com rises a bracket 57 attached to the base plate and adjustablethereon to an up-turned end of which is secured a leaf spring 58, on theother end of which is attached a movable contact point arm 59, the freeend of which is provided with a cam-engaging tip 60, preferably of hardsmooth steel or similar material. On this arm 59 is carried a platinumor tungsten movable contact point 61 adapted to cooperate with -astationary contact point 62 mounted on a bracket 63 longitudinallyadjustable on a condenser plate or cover 64 which is insulated in ansuitable manner from the base plate 7. ormally the contact points 61 and62 are in engagement but as the contact maker cam 61 is revolved thehigh parts of the said cam intermittently li the movable contact point61 out of engagement with the stationary contact point 62. During theperiod when the low parts of the cam 31 are passing under the tip of thearm 59 the spring 58 returns the movable contact point intoengagementwith the stationary contact point. 1

Between the base 7 and the cover 64 is clamped in any suitable manner acondenser 65 bridging the contact points 62 and 63.

Above the cam 31 extends the distributer arm sup ort 32 into the upperend of which is embe dad a metal bushing 66 which is threaded to receivea set screw 67 the upper end of the distributer arm support is alsopreferably provided with mo ed lugs 68 adapted to pass through a slot 69in the metal distributing arm or block 16, said set screw 67 serving torigidly hold said distributer arm or block on to the top of thedistributer sup ort, and said arm being slightly longitudina yadjustable on said support to permit the end16 to be brought intoelectrical en agement with the terminals or lates 15. he other end 16''of the distri uter fprojects on the opposite side thereof sufciently to,substantially counterbalance the end 16 To the top 0 the distributor armor bearing 16 is riveteda leaf spring 70 adapted to engage with thecentral contact point or plate 8 of the distributer.

gal force develope The centrifugal force, developed in the weights 25,28, 40 and 46 by the rotation of the shaft 20, acts to throw the weightsoutwardly radially from the axis of the shaft to a position where thisforce is balanced by the springs 51 and 54. The springs 51 and 54 beingnormally in the position shown in Fig. 6, the first movement of thepivot pins or studs 38 and 44 is substantially at angles to the axis ofsaid springs, as indicated by the arrows 71 Fig. 6, and such firstmovement is only slightly resisted by the springs. A considerablemovement of said pins in this position 0 erates to turn said sprin sabout their stu s 52 and 55 without stretc ing the springs to a greatextent. As the studs 38 and 44 continue to move about the axis of theshaft 20 and in their slots 39 and 45, under an increased centrifugalforce due to increased speed of the shaft 20, the direction of theirmotion more nearly approaches one axially of the springs; that is to saythey stretch the springs more and turn them less about their pivot insor studs 52 and 55. The resistance of t e springs to the motion of thestuds 38 and 44 therefore rapidly increases as the movement ordisplacement increases, and this resistance I have found to besubstantially proportional to variations in ,the centrifugal forcedeveloped in the weight at such varying speeds. Asa result of this theamount of angular movement of the top plate 33 with respect to thebottom plate 23 is substantially directly proportional'to variations inspeed of the shaft 20. The ends of the springs 51 and 54 which arerespectively seated in the kerfs 50 and 53, serve to retain the weights40 and 46 on their pivotal studs 38 and 44 without other securing means.These springs resist the advance of the (plate 33 by the centrifuby therotation of the weights about the shaft-20 and also serve to prevent thesaid weights 40 and 46 from sli ping off their pivot pins respectively.

y making the cam 31, distributor arm support 32 with the positioninglugs 68 and plate 33 unitary there can be no angular displacement ofthese parts with respect to each other, and these units may be made inreat numbers exactly alike, and all assem ling and adjusting of saidthree arts is absolutely eliminated. Moreover, i for any reason thatpart requires to be replaced in an old machine, it is only necessary toremove the cap 4, removethe plate 7 and draw the entire speed res onsivemechanism as a unit, wi th the she 20, from the cap 2. The ends of thesprings 51 and 54 may be then released from the kerfs 50 and 53 and thecombined cam, distributer support and top plate with the studs 38 and 44ma be drawnou't of the other parts and of]? o the e ension 30, and a newone as .readily aek place, without in any manner disturbing theadjustment of the timer or distributer, or disturbing the adjustment ofthe speed responsive mechanism thereto.

It will be seen that each Weight or governing member is loosely held orsupported and at two points only, namely, at the pivotal point at oneend of each governing member and at the pivotal point Where twocooperating members are pivoted together. To prevent these members fromtipplng on these pivotal points the holes for the pivotal pins througheach member are so disposed that the weight of each member on one sideof a line drawn through these pivotal points is balanced. As indicatedin Fig. 6 the weight of the member on one side of the dot and dash line72-72 balances the weight of that part of the other side of said line.

The weight of each governing member is thus balanced on each side of theline passing through the two points at which each Weight is pivoted.This feature of construction makes it possible to loosely pivot themembers 22, 25, 40 and 46 together as above described and at the sametime avoids any tendency of the members to turn about the lines,connecting their pivoted points, as axes. It also prevents any bindingor cramping of the members on their pivots and reduces the frictionbetween the members, or between the members and the plate, as they moveor slide over each other and over the plate 23. This constructionrenders the governing members very sensitive and responsive tovariations in the speed of the drive shaft.

It is, of course, to be understood that the number of leads of thesecondary circuit will vary with different engines dependent upon thenumber of cylinders to be ignited and consequently the number ofprojections 14 will be varied accordingly.

VVhat I claim and desire to protect by Letters Patent of the UnitedStates is:

1. In a spark forming and controlling device the combination of acasing, a driving shaft, a journal for said drive shaft in said casingand extending upwardly into said casing and forming a step or thrustbearing, a plate rigidly secured to said shaft and resting on said stepbearing, a second plate, a combined cam and distributer arm supportrigidly secured to said second plate and mounted and supported on thetop end of said shaft and rotatable with respect to said shaft and meansoperatively attached to said plates and located below said firstmentioned plate to vary the angular position of said top plate and theparts carried thereby with respect to said drive shaft.

2. In a spark forming and controlling device the combination of acup-shaped casing, a driving shaft, a journal for said drive shaft insaid casing, and extendlng upwardly in said casing and forming a step orthrust bearing, a plate rigidly secured to said shaft and supported onsaid thrust" bearing, a second plate loosely journaled on said shaftabove said first mentioned plate, means operatively attached to saidplates and located below said first mentioned plate and surrounding saidjournal to vary the angular position of said top plate with respect tosaid shaft proportionally to variations in the speed of said driveshaft, and to drive said second mentioned plate from said drive shaft,and a contact maker cam and distributer arm support of insulatingmaterial unitarily united to and supported by said second mentionedplate.

3. In a spark forming and controlling device the combination of a cu-shaped casing, a driving shaft, a journal or said drive shaft in saidcasing, and extending upwardly in said casing and forming a step orthrust bearing, a plate rigidly secured to said shaft and supported onsaid thrust bearing, a second plate loosely journaled on said shaftabove said first mentioned plate, means operatively attached to saidplates and located below said first mentioned plate and surrounding saidjournal to vary the angular position of said top plate with respect tosaid shaft proportionally to variations in the speed of said driveshaft, and to drive said second mentioned plate from said drive shaft,and a combined contact maker cam and distributer arm support of bakelitemounted on said second mentioned plate and supported thereby andunitarily molded thereto.

4.. In a spark forming and controlling device the combination of a driveshaft comprising. a main portion and a reduced upper end, a plate, acombined cam and distributer arm support of insulating material unitedby molding to said plate and provided with an axial bore fitting overthe reduced end of said shaft, a plate secured to said drive shaftadjacent the shoulder between the main portion and the reduced portionof said shaft, a weight pivoted at one end to said first mentionedplate, a weight pivoted at one end to said second mentioned plate,

means to pivot the free ends of said weights together, said weightsbeing below said plate on said main portion of said shaft, a journal forsaid drive shaft extending to said plate on said drive shaft and forminga stop or thrustbearing for said plate on said main portion whereby saidplates, weights and parts carried thereby are all mounted on said shaftand supported on said thrust bearing.

' 5. In a spark forming and controlling device the combination of adrive shaft comprising a main portion and a reduced upper end, providinga shoulder between them, a plate, a combined cam and distributer armsupport of insulating material unitarily united by molding to said plateand provided with an axial bore fitting over the reduced end of saidshaft and supported on said shoulder, a plate secured to said driveshaft adjacent said shoulder, and a pair of L-shaped weights havingtheir ends loosely pivoted, respectively, to said plates and locatedbelow said plate on said drive shaft, and having their free endsoverlaping and loosely pivoted together and a ournal for said driveshaft extending to said plate on said drive shaft and forming a thrustbearing therefor.

6. In a spark forming and controlling device the combination of a driveshaft, a top plate, a bottom plate, a weight below said bottom platepivoted at one end to said top plate on a pivot extending through saidbottom plate, a weight below said bottom plate pivoted at one end tosaid bottom plate, pivotal means connecting the free ends of saidWeights, a complemental pair of similar weights similarly pivoted,respectively, to the top and bottom plates and to each other andsymmetrically disposed with respect to said first mentioned pair ofweights, and yielding means tending to hold said plates in a fixed andangular relation with respect to each other and yielding under theaction of centrifugal force in said weights to counterbalance saidcentrifugal force and to regulate the amount of angular movement of saidtop plate with respect to said bottom plate.

7. In a spark forming and controlling device the combination of a topplate, a bottom plate, a pair of substantially L-shaped Weights pivotedat one end to said top plate and said bottom plate, respectively, andhaving their free ends pivoted together, said weights being disposedbelow said bottom plate, and being disposed on one side of a linepassing through the axis of said shaft, a similar pair of similarweights similarly pivoted, respectively to said top and bottom platesand to each other and symmetrically disposed below said bottom plate onthe opposite side of said line, a drive shaft to which said bottom plateis rigidl secured, a journal for said drive shaft ormin a thrust bearingupon which said bottom p ate is supported and rotated, and a contactmaker cam mounted upon said top plate in axial alinement with saidshaft.

8. In a spark forming and controlling device the combination of a topplate, a bottom lplate, a pair of substantially L-shaped weig ts pivotedat one end to said top plate and said bottom plate, respectively, and

having their free ends pivoted together, said,

weights bein dis osed below said bottom plate, and being isposed on oneside of a line passing through the axis of said shaft,

a similar pair of similar weights similarly pivoted, respectively, tosaid top and bottom plates and to each other and symmetrically disposedbelow said bottom plate on the opposite side of said line, a drive shaftto which said bottom plate is rigidl secured, a journal for said driveshaft orming a thrust bearing upon which said bottom p ate is supportedand rotates, and a combined contact maker cam and distributer armsupport of insulating material unitarily united to said top plate andsupported by said shaft.

9. In a spark forming and controlling device the combination of a driveshaft having a reduced upper end forming a shoulder, a combined cam, anddistributer arm support journaled on said reduced end, a top platerigidly secured to said combined cam and distributer arm support andbearing against said shoulder, a bottom plate rigidly secured to saidshaft adjacent said shoulder, a weight below said bottom plate pivotedat one end to said bottom plate, a second weight below said bottom plateand pivoted at one end to said top plate on a pivot extending freelythrough said bottom plate, pivotal means connecting the free ends ofsaid weights together, a journal for said shaft having an upper endforming a thrust or step bearing upon which said bottom plate bears anda spring tending to hold said plates in a fixed relation with respect toeach other and yieldingly resisting the pull of centrifugal forcedeveloped in said weights.

10. In a spark forming and controlling device the combination of a driveshaft, a plate having a center hole or opening and an 'anuular flangeextendin on one side of said plate co-axially with said openings, saidplate being provided with a recess in its opposite side larger than andco axially with said flange, a combined cam, a distributer arm supportof insulating material molded on, over and around'said flange and intosaid hole and recess, and rovided with an axial bore into which saidupper end of said shaft smoothly fits, a spark advancing and retardingmechanism operatively connecting said driving shaft and said plate, acontact device operated by said cam, a distributer arm secured to thetop of said support and a series of contact plates cooperating with saiddistributer arm.

11. In a spark formin and controlling device the combination 0% a driveshaft, a plate having a central hole or openin and an annular flangeextending on one side of said plate co-ax ally with said opening andprovided with a recess on the other side balance the centrifuga providedwith an axial bore into which the upper end of said shaft smoothly fits,a spark advancing and retarding mechanism operatively connecting saidplate and said drive shaft, a contact device operated by said cam, ametallic distributer arm secured to the top of said support andextending transversely on both sides of the axis of said support, acircular series of contact points, one end of said distributer arm bemgarranged to cooperate with said contact points, and the other end ofsaid arm formmg a substantial counterbalance for that end of said armwhich cooperates with said contact points.

12. In a spark forming and controlling device the combination of ahollow cup-like casing, the base plate of a contact maker securedto thetop of said casing, a driving shaft provided with an extension passingthrough said base plate, a contact maker operating cam journaled on saidextension, a contact maker operated thereby and mounted on said baseplate and a cam advancing and retarding mechanism operated bycentrifugal force and operatively connecting said cam and drive shaft,said mech anism comprising a plate operatively connected to said cam, aplate rigidly secured to said drive shaft, a weight pivoted atone end onsaid first mentioned plate on a pivot passing through said plate on saiddrive shaft, a weight pivoted to said second mentioned plate and havingits free end pivoted to the free end of said first mentioned weight,said weights being below said plates and within said cup-sha ed casing,a s ring tending to hold said p ates in a pre etermined position and ocrating to counterlforce developed in said weights and the distributerarm rigidl secured to said shaft and rotated therewit and transverselyadjustable thereon.

13. In a spark forming and controlling device the combination of a driveshaft a governing mechanism driven b said drive shaft, and includin aplate driven by said shaft through said and angularly advanced andretarded by said governing mechanism, said plate being provided with anannular flange projecting rom one side thereof and with an annularrecess co-axial with the o enin through said flange and located on t eot er side of said plate and a combined contact maker cam anddistributer arm support of bakelite governing mechanism molded on saidplate unitarily therewith' over, around, and into said recess on theopposite side of said plate.

14. In a spark formin and controlling device the combination 0% a driveshaft, a plate secured to said shaft, a second plate mounted to turnindependent of said shaft on an axis in substantlal alinement with theaxis of said shaft and a pair of substantially L-sliaped Wei hts or govrnin members on the same si e of bot sai lates, each member having oneof its ends oosely pivoted to one of said plates res ectively, saidmembers having the1r free end; respectively overlapping and disposed inparallel planes, and a pivotal connection loosely pivoting same togetherintermediate of their ends, the weight of each member being balanced oneach side of a line drawn through the pivotal points thereof.

In witness whereof I have hereunto set my hand this fourth day of April,1917.

ARTHUR ATWATER KENT.

